IntroductIonMucopolysaccharidosis (MPS) is an inherited metabolic disorder, which is part of the lysosomal disorders; the main characteristic is the deficiency of lysosomal enzymes responsible for the degradation of glycosaminoglycans such as dermatan and heparan sulfate, as a consequence of mutations in various genes. 1,2 This failure induces intralysosomal accumulation in the extracellular space, interfering with the degradation of other macromolecules.This process produces chronic cell degeneration affecting multiple organs and systems, such as bones, liver, spleen, heart, eyes, and CNS. 2 The global incidence of all MPS is one per 25,000 individuals.MPS are autosomal recessive inheritance disorders, except for type II, which is X-linked recessive inheritance.There are seven types of MPS, taking into account enzyme deficiency and clinical characteristics. 2 Mucopolysaccharidosis (MPS) II, or Hunter syndrome is caused by iduronate-2-sulfatase deficiency, which has been reported in >300 genetic mutations. 1,3 Its estimated incidence is one per 100,000 individuals. 3 The initial clinical manifestations vary widely among individuals, even those with the same mutation, typically including recurrent respiratory infections, coarse facial features, joint stiffness, otitis media, umbilical/inguinal hernias, cardiomyopathies, hepatosplenomegaly, and short stature.Neurological symptoms